Keeping track of people and equipment in underground areas can be complicated. Confined spaces and rock may interfere with communication signals. Workers in underground areas, such as mines or tunnels, face many environmental hazards, including potential cave-ins, gas leaks, and other harmful situations. Because underground tunnel networks may extend over a large area, rescuers searching for trapped workers may have difficulty locating trapped workers. Further, trapped workers may have difficulty finding self-rescue tools and supplies deployed throughout a tunnel network.
Some previous approaches to providing communication in underground areas include adding independent underground radio tracking networks in addition to existing underground radio communication networks. However, such approaches may not be easily extensible and may compete with other underground utilities for power, space, etc. Extending, upgrading, and maintaining underground utilities for such independent radio networks may further complicate existing underground communication systems.